A plastic box `1. 5\ m` long, `1. 25\ m` wide and `65\ c m` deep is to be made. It is to be open at the top. Ignoring the thickness of the plastic sheet, determine: The area of the sheet required for making the box. The cost of sheet for it, if a sheet measuring `1\ m^2` cost `R s .20`

Explanation

given,`l=1.5cm`

`b=1.25cm`

`h=0.65cm`

so total area of box`= lb+2(bh+hl)`

`=1.5xx1.25+2(1.25xx0.65+0.65xx1.5)`

`=5.45cm^2`

so the cost of sheet `=5.45xx20`

`=109 rupees`